The use of unsaturated polyester compounds in combination with thermoplastic resins and fillers to produce molding compositions is well known. Such molding compositions are disclosed in U.S. Pat. No. 3,772,241 to Kroekel. These compositions, and like compositions intended to polymerize when molded under heat and pressure, are generally combined with fillers and chopped glass, produced from roving, to produce molded products having appearance surfaces, that is, the surface exposed to view, with minimum irregularities or undulations, known as Class A surfaces.
The use of chopped glass as reinforcement in such molding compounds is well known. Such chopped glass is produced in the form of individual strands which are sized, gathered into roving, which roving is then chopped to the desired length and incorporated into the resin composite prior to molding.
Such sizes as are used generally comprise a polyester emulsion base, a lubricant, film formers, and the like and are extremely important in imparting to the reinforcing glass its ability to be wetted out by the molding compound. These sizes are also important in that they protect the glass in its handling subsequent to being sized and are influential in minimizing the amount of fuzz and fly which is produced on, and with, the glass, the fuzz and fly having a decided affect upon the appearance surface of the molded product.
Many lubricants for inclusion in such sizes are known. However, there has now been discovered a lubricant system comprising a combination of lubricants which decidedly reduces the fuzz content of the chopped glass and, surprisingly, reduces the fuzz content of the chopped glass to a level lower than that attained when the lubricants are employed individually.